1. Field of the Invention
The present invention relates to a device for moving a long article vertically, while holding it always in a horizontal position, no matter what portion of the long article might be pushed, and a paper cutting machine utilizing the device.
2. Description of the Prior Art
The prior art will be described by referring to a paper cutting machine as an example of the long article. As shown in FIG. 7, for example, the paper cutting machine is constructed such that a rail 3 is supported at one end on a bedplate 1 by a support 2 and such that a paper holder 4 is carried on the rail 3 so as to move toward and away from the rail 3. In the cutting operation of paper using this cutting machine, the rail 3, which has its base portion supported by the support 2, is pulled up at its other, free end portion, and the sheets of paper to be cut are placed on the bedplate 1. Next, the rail 3 is pushed down on its base portion to hold the paper with the paper holder 4, until a locking mechanism 6 carried on the free end portion of the rail 3 is retained by a retainer 7 which is fixed on the bedplate 1, thereby to maintain the holding of the paper by the paper holder 4. Next, a slider 5 (as should be referred to Japanese Utility Model Application No. 26776/1988) fitted on the rail 3 is slid to cut the paper by a rotary blade which is carried on the slider 5. Moreover, the cutting of the paper is positioned with respect to the edge of the paper holder 4 so that the rotary blade cuts the paper while turning with its side face contacting with the edge of the paper holder 4.
The paper cutting machine thus constructed will raise no serious problem if the number of sheets of paper placed on the bedplate is small. If this number is large, the paper sheets are held at first from the side of the base end of the rail by the paper holder because the paper holder moves together with the rail when the rail is depressed on its base end. As a result, the stacked sheets of paper are displaced by the depression of the paper holder. If the cutting operation is carried out in the state of displacement, the sheets of paper cannot be accurately cut, resulting in irregular edges. For positioning the cutting of the paper sheets, moreover, the paper holder has its leading end raised together with the rail from the base end of the rail so that the cutting position is difficult to determine with reference to the edge of the paper holder. In addition, the cutting operation cannot be started before the cutting position is confirmed by depressing the rail several times. After these positioning operations, the stacked sheets of paper are so displaced that they cannot be cut to an accurate size.
In order to prevent the displacement of the paper sheets and to facilitate the positioning of the cutting operation, it is sufficient to move the paper holder or the rail vertically in parallel with the bedplate. In order that the rail may be able to move vertically while being in parallel with the bedplate, the rail has to be moved down vertically in parallel with the bedplate no matter what position of the rail or the paper holder such as the free end portion of the rail might be depressed. This is because the slider may be located in any position to depress the rail therethrough.